Front fork colour now the least of my worries

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kainsworth
Posts: 36
Joined: 13 Jul 2016 20:47
Location: Heathrow

Front fork colour now the least of my worries

Post by kainsworth »

Hi

I have a lovely yellow 350 Sport from 1978 ish, black frame, cast wheels etc with black fork sliders which could do with a bit of tidying up as they have a few scratches and look hand painted or i could polish them as bare alluminium, my question was what year did they go black and should they be unpainted anyway?


Regards

kevin
Last edited by kainsworth on 08 May 2020 16:41, edited 1 time in total.
mbmm350s
Posts: 666
Joined: 22 Jun 2018 10:18
Location: Reading UK
Location: Berkshire UK

Re: Front fork colour

Post by mbmm350s »

Hi,
May be this isn't the answer you were looking for!
I think you should do whatever you think looks best and makes you enjoy the bike more and hang what anyone else says.

Obviously yellow was never the standard colour for a sport,
so whether the sliders should be painted or polished doesn't really matter.

A pretty good comparison of models mostly taken from factory brochures can be found here,
except the later 1977/8 models usually had a different seat,
and sports could be ordered with a second disk.
http://www.motomoriniclub.com/lemoto/350stradali.php

Its interesting that more and more painted parts replaced polished as the years went by, most likely for cost saving reasons.
Mark
Mepstein
Posts: 147
Joined: 27 Apr 2016 02:38
Location: Newark, Delaware
Location: Newark, Delaware, USA

Re: Front fork colour

Post by Mepstein »

If you polish them and don't like the look, it will be very easy to scuff and paint.
3potjohn
Posts: 1243
Joined: 02 Jun 2007 13:58
Location: Devon

Re: Front fork colour

Post by 3potjohn »

My 83 bike has black ones. This eventually gets chipped. I recently repainted them using Hammerite Satin Black with their primer undercoat ( as it’s not a ferrous metal) It’s getting plenty of time to properly cure but even so when I have done this on another make of bike it will need repeating at some stage, depends on the road surface somewhat.
The bikes I have with unpainted forks are less problematic.
John
kainsworth
Posts: 36
Joined: 13 Jul 2016 20:47
Location: Heathrow

Re: Front fork colour

Post by kainsworth »

Thanks for the replies, i will have a think
kainsworth
Posts: 36
Joined: 13 Jul 2016 20:47
Location: Heathrow

Re: Front fork colour now the least of my worries

Post by kainsworth »

HI it would appear that i need not have worried about the fork colour too much, i have not had the 350 S too long and was always a bit unimpressed with the performance which compared to my 500 Sei is very poor, i just assumed that was how it was etc, anyway whilst self isolating around and about I noticed that it was smoking quite heavilly from one pipe, wait till cold, compression test, throttle wide open, 170 front piston and very nearly 75 on the rear..... I did it about 8 times to check and the back cylinder is very poor

I have had a quick search on here and there is lots of posts about pistons. barrels etc, I assume its pretty straight forward and worst case its 2 new pistons and a rebore and can be done at home fairly easy?
3potjohn
Posts: 1243
Joined: 02 Jun 2007 13:58
Location: Devon

Re: Front fork colour now the least of my worries

Post by 3potjohn »

Bad luck. Best you look at the parts for sale section now, there is a chance of a solution perhaps, given you do not know what is damaged. It is easy to work on though.
MickeyMoto
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Joined: 22 Nov 2008 17:41
Location: Even further oop North

Re: Front fork colour now the least of my worries

Post by MickeyMoto »

I sent my barrels and head to SEP at Kegworth. They refurbished the parts. You may find it cheaper to have new liners made as it means you can keep your pistons.

They also did my crankshaft. You may find your valve guides need replacing, too.

You can do the top end without removing the engine.

Mike.
kainsworth
Posts: 36
Joined: 13 Jul 2016 20:47
Location: Heathrow

Re: Front fork colour now the least of my worries

Post by kainsworth »

Hi, I have pulled the rear cylinder apart and the top ring had broken in two, no scores, no missing bits so will replace. The liners seem to have very little wear so pretty lucky really. The one bit I am not sure about is do piston rings come in plus sizes? Its a 62mm piston but not accurate enough to know if its plus anything or does that matter? Cant see any markings apart from what look like two "O"s on the piston top. I also cant seem to see a headgasket?

Loved it with low power now cant wait to get it working with two functioning pistons!

Regards

Kevin
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72degrees
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Joined: 31 Aug 2007 21:24
Location: West Midlands

Re: Front fork colour now the least of my worries

Post by 72degrees »

kainsworth wrote:Hi, I have pulled the rear cylinder apart and the top ring had broken in two, no scores, no missing bits so will replace. The liners seem to have very little wear so pretty lucky really. The one bit I am not sure about is do piston rings come in plus sizes? Its a 62mm piston but not accurate enough to know if its plus anything or does that matter? Cant see any markings apart from what look like two "O"s on the piston top. I also cant seem to see a headgasket?
Kevin
Rings do come in oversize : .2 I think , .4. and .6 versions ? though the last time I bought pistons NLM had only got 62.6 or the '375' ones. I haven't got a standard piston to hand to check markings but a decent vernier guage could confirm. In any case, best to 'gap' (or at least check) the new rings to your cylinder. I've never known a Morini run with no head gasket at all though a 'racer' may have experimented. Sure an alloy one isn't 'stuck' to the cylinder? My 375 'race' engine runs with no base gaskets, but I think total absence of head gasket might be pushing things a bit on compression ratio for road use.
kainsworth
Posts: 36
Joined: 13 Jul 2016 20:47
Location: Heathrow

Re: Front fork colour now the least of my worries

Post by kainsworth »

Hi yes I am an idiot the headgasket was stck to the barrels.........
jb666
Posts: 182
Joined: 02 Nov 2006 22:20
Location: Ashford, Kent

Re: Front fork colour now the least of my worries

Post by jb666 »

Not an idiot just not looking at the wrong bit!!!

As everyone has said rebuilding the top end is possible with the engine in the frame - just take your time and mind your knuckles!!

John.
3potjohn
Posts: 1243
Joined: 02 Jun 2007 13:58
Location: Devon

Re: Front fork colour now the least of my worries

Post by 3potjohn »

I have 2 old pistons with some scoring on the skirts. One has 62.4 stamped on it and the other has only a 4.
I had a broken ring on a German offering, it jumped into an adjacent ring groove too. It made for poor starting and poor acceleration with a sound a bit like a steam engine. That’s the Rocket not the Mallard.
Some info here may help.
http://www.motomoriniclub.nl/tabel.html
John
kainsworth
Posts: 36
Joined: 13 Jul 2016 20:47
Location: Heathrow

Re: Front fork colour now the least of my worries

Post by kainsworth »

Thanks everyone

I am now convinced it is on standard bore and have ordered the parts, now where is that postman.......

Regards

Kevin
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